Increasingly, motor vehicles are becoming equipped with wireless communication devices (hereinafter “user equipment”) to allow various advanced capabilities coordinated by way of remote computer networks. For example, user equipment allow remote monitoring of vehicle maintenance and performance as well as enabling roadside assistance, together with map rendering programs, by way of global positioning satellite services or network positioning or the like. In yet another example, user equipment is coupled in vehicles to allow cellular phone service by integrating user equipment into telematics display consoles or in the ceiling/roof of the vehicle. Other services provided by user equipment include access to social media programs, entertainment, e-mail or Internet browsing over IP networks by way of WiFi or advanced cellular networks, such as Long Term Evolution (LTE) and LTE-Advanced (LTE-A). Still other user equipment coupled in motor vehicles allow for fleet operations or enable ad hoc networks for large fleets of commercial delivery trucks, rental vehicles or other grouped or classified vehicles. In the near future, motor vehicles utilized by first responder vehicles (e.g. police, fire, public safety and emergency medical technician vehicles) in at least the United States will be equipped with user equipment operating in the 700 frequency D-block band to access the First Responder Network Authority (FirstNet) which will have architecture similar to LTE.
The environment and operational lifetimes of user equipment coupled to motor vehicles are unlike traditional user equipment such as cellular telephones, tablets and laptop computers. For example, design requirements of a particular motor vehicle may require that radio frequency (RE) circuits (RFICs, power amplifiers, frequency generation, crystals, active/passive frequency selective components, switches as discrete or modules or system in package (SIP)) are integrated into the vehicle's telematics console, on board diagnostic (OBD) interface, ceiling or steering wheel assembly, among other internal cabin locations. Alternatively, SIP, RF circuits and the RFICs may be integrated into modules outside the vehicle chassis. As such, thermal management of user equipment over the products' lifetime can be problematic.